net/mlx5: Vport LAG creation support

Add interfaces for issuing CREATE_VPORT_LAG and
DESTROY_VPORT_LAG commands.

Used for receiving PF1's eth traffic on PF0's
root ft.

Signed-off-by: Aviv Heller <avivh@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>